It has long been suspected, and earlier studies have confirmed, that there is a specific factor or activity in mammalian serum and plasma which supports epidermal cell movement. [Stenn, British Journal of Dermatology, Vol. 98, pages 411 (1978); Stenn et al., Arch. Dermatol. Res., Vol. 264, pages 3-15 (1979); U.S. Pat. No. 3,948,875].
Recently efforts have been directed toward the characterization of the epidermal cell migration promotion activity in serum. See Levene, M., Br. J. Dermatol., Volume 86, pages 481-490 (1972); Coombs, V. A., Nissen, B. K. and Marks, R., Arch. Dermatol. Forsch, Vol. 249, pages 367-372 (1974); Stenn, K. S. and Dvoretzky, I., Arch. Dermatol. Res., Vol. 264, pages 3-15 (1979); Mitrani, E. and Marks, R., Br. J. Dermatol., Vol. 99, pages 513-518 (1978); Griffiths, G., Jones, H. M., Cryer, J., Kay, J. and Marks, R., J. Invest. Dermatol., Vol. 46, 430 (abstr.) (19781); and Ooka, H., Yamauto, K., Okuma, Y., Suga, S. and Wakasugi, M., Exp. Gerontol., Vol. 10, pages 79-83 (1975). Mitrani et al., for example, describe a method for fractionating serum by combining ammonium sulfate precipitation and molecular sieve chromatography.
Other spreading factors have been described [Lipton, A., Klinger, II, Paul, D. and Holley, R., Proc. Natl. Acad. Sci. U.S.A., Vol. 68, pages 2799-2801 (1971); Wolf, L. and Lipton, A., Exp. Cell. Res., Vol. 80, pages 499-502 (1973); Burk, R. R., Proc. Natl. Acad. Sci. U.S.A., Vol. 70, pages 369-372 (1973); R. R. Burk, Exp. Cell. Res., Vol. 101, pages 293-298 (1976); Wall, R. T., Harker, L. A. and Striker, G. E., Lab Invest., Vol. 39, pages 523-529 (1978); Zetter, B. R., Nature (London), Vol. 285, pages 41-43 (1980); and Leonard, E. T. and Skeel, A., Exp. Cell. Res., Vol. 102, pages 434-438 (1976)].
Recently a serum spreading factor for fibroblasts was isolated by Knox et al. (Exp. Cell. Res., Vol. 123, pages 421-424 (1979)) and Whateley et al. (Biochem. J. Vol. 185, pages 349-354 (1980)) from fetal calf serum. The protein differs from the protein of the present invention by origin, purification and chemical properties and activity.
It is an object of the present invention to provide an epithelial cell movement enhancing protein and a method for its preparation.